Using avian myeloblastic (AMV) virus reverse transcriptase we have constructed a cDNA library of rat uterus mRNA. The cDNA was cloned into the Eco R-1 site of the expression vector lambda gt 11, a bacteriophage of E. coli. Upon induction with isopropylthio-beta-galactoside (IPTG), hybrid protein expression in the recombinant yielded at least five positive clones for myosin light chain kinase by the criteria of I-125 protein A immunological cross reactivity with anti-myosin light chain kinase antibody. Progress is being made on synthesizing a cDNA library of adult turkey gizzard mRNA. We are developing mRNA denaturation techniques to make the gizzard mRNA a better substrate for the AMV reverse transcriptase enzyme.